The present invention relates to a method of manufacturing a mask and a manufacturing technique of a semiconductor integrated circuit device, and more particularly to a technique effectively applied to an exposure technique.
A standard mask used in an exposure technique has a structure in which a light-shielding pattern, composed of a metal film made of, for example, chromium or the like, is provided on a mask substrate transparent to exposure light. The mask is manufactured in the following manner, for example. First, a metal film made of chromium or the like for shielding light is deposited on a transparent mask substrate, and an electron beam sensitive resist film is coated thereon. Subsequently, electron beam is irradiated to a predetermined portion on the electron beam sensitive resist film by the use of an electron beam writing apparatus or the like, and then the resist film is developed to form a resist pattern. Thereafter, the lower-layer metal film is etched with using the resist pattern as an etching mask, thereby forming the light-shielding pattern composed of the metal film. Finally, the remaining electron beam sensitive resist film is removed to manufacture the mask. However, in the mask having the above-described structure, there are a problem of the fact that the costs become high because the number of process steps is large, and a problem of the fact that the dimensional accuracy in the process is reduced because the light-shielding patterns are processed by isotropic etching. As a technique taking into consideration these problems, for example, Japanese Patent Laid-Open No. 5-289307 discloses a technique in which the light-shielding pattern on the mask substrate is composed of a resist film by making use of a standard electron beam sensitive resist film and a light sensitive resist film having a transmittance of 0% to the ArF excimer laser. Note that in pp. 63 to 75 of “Story about the photomask technique” first impression of the first edition published on Aug. 20, 1996 by Kogyo Chosakai Publishing Co., Ltd, a mask-defect inspection technology and a mask-defect repair technology and the like are described in detail.